Nozzle construction for refrigerated cabinets



June 2l, 1966 s. Br-:cKwlTH ETAL. 3,256,799

NOZZLE CONSTRUCTION FOR REFRIGERATED CABINETS FIG, 3

June 21, 1966 s. BECKWITH ETAL. 3,256,799

NOZZLE CONSTRUCTION FOR REFRIGERATED CABINETS Filed Dec. 9, 1963 2Sheets-Sheet 2 ooooooooooooo OOOOOOOOOOOO@ oooooooooooo United StatesPatent O 3 256,799 NOZZLE CONSTRUC'IGN FOR REFRIGERATED CABINETSSterling Beckwith, Libertyville Township, and Robert E.

This invention relates to improved constructions for use in the handlingof two or more air curtains which are to be moved in side-by-siderelationship. Specifically, the invention is directed to novelconstructions which are designed to effect the character of the movingair curtains whereby they can be moved in a highly efficient manner. l

The instant invention will be described with reference to refrigeratedcabinet constructions. In such constructions, air curtains are movedacross :an access opening for the cabinets and the character of thecurtains is important with regard to efficient operation of theconstruction. It will |be understood, however, Ithat the nozzlesemployed herein can be utilized for the handling of air streams in otherconstructions where the necessary characteristics of the streams aresimilar to the characteristics required of streams in refrigeratedcabinets.

In an application of Hagen et al., Serial No. 54,077, filed September 6,1960, and in the issued Simons Patent No. 2,862,369, there are describedrefrigerated display cabinets which are provided with access openingsexposed to the atmosphere while still being capable of maintaining thecontents in a refrigerated state. Loss of refrigeration from theenclosed space through the access opening is reduced in a highlyeffective manner in these constructions by the use of a gaseous,preferably air, curtain which is continuously advanced across the openside from one edge of the opening to the' opposite edge. The air curtainin these constructions is adapted to be formed of adjacent panels ofair, with the innermost panel comprising a refrigerated cold lair panel,and with one or more outer panels having temperatures approaching theambient temperature. It has been found that it is desirable torecirculate the inner cold air panel and to provide means forcirculating the adjacent guard panels, to conserve the refrigeration andto maintain the enclosed space in a satisfactory refrigerated state.

In these constructions there are described :assemblies which includenozzles extending across the bottom edge of the access opening to directthe Iair panels upwardly across the opening towards inlets which extendacross the top side of the access opening. As an alternative, thenozzles are located across the upper edge for projecting the air panelsdownwardly toward inlets arranged Iacross the bottom edge. It is alsocontemplated that the air nozzles be located across one of the lateraledges of the opening for directing the corresponding air panels acrossthe opening toward inlets in the opposite edge. Because of the moredesirable effect of gravity on the higher density cold air, it has beenfound preferable to provide the air curtain with a downward movementfrom nozzles across the top to inlets across the bottom. llhe followingdescription will refer to this preferred construction, although it willbe understood that the concepts to be described are also applicable toother directions of ow.

In the use of cabinets of the type described, it is, of course,desirable to provide maximum efficiency insofar as the amount of powerconsumed is concerned. In refrigeration systems of thisV type, theconsumption of power is primarily due to the refrigeration of the movingair streams which pass over the access opening for the cabinet. To asomewhat lesser degree, power is con- Pice sumed during defrostingycycles and due to the vdriving of fans for circulation of the streams.As far as the refrigeration of the streams is concerned, a major factorcontributing to the amount of power consumption is the loss ofrefrigeration (or intake of heat) through the access opening.

Loss of refrigeration can be attributed to a substantial degree toturbulence which is set up between moving air streams and still airadjacent the moving air streams. Specifically, it has been found thatthe movement of a stream adjacent still air or adjacent a stream movingat a substantially different speed will create turbulence and willresult in a whipping action. The moving streams of air whencharacterized by such action, move out of their intended pathsperiodically, and large masses of the air can be completely lost insofaras the circulating streams are concerned. Where these masses arerefrigerated, the natural result is to increase the load on therefrigerating means for the cabinet so that the loss of refrigerationcan be accommodated.

It is an object of this invention to provide a refrigerated cabinetconstruction which includes means for de creasing the amount of powerconsumption necessary to achieve `a desired level of refrigeration.

It is a more particular object of this invention to provide a cabinetconstruction of the type described which is provided with unique outletnozzles for passing refrigerated streams across an access opening, whichnozzles are effective to reduce the turbulence set up between thestreams and the ambient air to thereby increase the efliciency ofoperation of the cabinet.

These and other objects of this invention will appear 'hereinafter andfor purposes of illustration but not of limitation, specific embodimentsof the invention are shown in the accompanying drawings in which:

FIGURE 1 is an elevational View partly cut away of a refrigeratedcabinet characterized by the features of this invention;

FIGURE 2 is an enlarged fragmentary view in section illustrating oneform for the nozzle constructions of this invention;

y FIGURE 3 is an enlarged fragmentaryv View in section illustrating analternative nozzle construction;

FIGURE 4 is an enlarged fragmentary view in section illustrating anadditional form of a nozzle construction; U FIGURE 5 is an enlargedfragmentary view in section illustrating a further alternative form ofnozzle construcion;

FIGURE 6 is an enlarged fragmentary view in section lllustrating anotherform of nozzle construction;

FIGURE 7 is :a fragmentary plan view of air passage inean suitable foruse in the construction of FIGURE FIGURE 8 is a fragmentary view of analternative form of air passage means suitable for use in theconstruction of FIGURE 6.

As discussed above, the improvements of this invention are directed toconstructions which employ air curtains moving in side-by-siderelationship in an unconfined manner. These improvements arespecifically directed to refrigerated enclosures of the type whichdefine an access opening in one wall whereby communication with thespace within the enclosure can be accomplished. The enclosures orcabinets of this invention are provided With a plurality of nozzlesarranged in side-by-side relationship across one edge of an accessopening and corresponding -inlets are located across the opposite edgeof the access opening. The inner nozzles and inlets are provided for thepassage of a refrigerated stream across the access opening while theadjacent outer nozzles and inlets circulate progressively warmer airpanels. The inner refrigerated stream is circulated through a passagehaving refrigeration coils located therein and one or more of the outeradjacent streams may also be refrigerated.

In accordance with the practice of this invention, it has been foundthat if means are provided for controlling the circulation of the airpanels in a certain manner, then a greater degree of efficiency, insofaras loss of refrigeration is concerned, can 'be obtained.

Specifically, it has been found that reduction in turbulence can beachieved lby providing for control of the speed of circulation =of theair streams. Thus, if the portions which contact the relatively stillambient air move at a slower speed than other portions vof the stream,reduction in turbulence can be achieved.

The specific constructions of this invention which are employed forachieving the desired results comprise nozzles having unique designs.Honeycomb material is preferably employed for the construction of thesenozzles since this material is available in a form which is suitable forthe purposes of this invention. Thus, this material is characterized bya plurality of small passages aligned in parallel relationship and thematerial is also adapted to be provided in a greater number of shapesand sizes. It will be understood, however, that the provision of otherconstructions which have the same characteristics as honeycomb materialsis contemplated for use in accordance with this invention.

The nozzles employed in the cabinets of this invention are designedwhereby they will affectl the rate of movement of the streams of airwhich pass out of the nozzles for movement across the access opening ofthe cabinet. Specifically, the nozzles are designed whereby the outerportions of the streams which contact the ambient air, or which contactslower moving air streams, are passed across the opening at a relativelylow speed to effect the desired decrease in turbulence.

The nozzle constructions are also capable of affecting the speed of theair streams whereby approximately the same rate of movement at theinterface of adjacent panels can be maintained. This `capability of thenozzle constructions serves to maintain a high degree of laminar ow inthe air streams which also results in a more uniform temperaturecondition in the adjacent streams. This condition has also beenrecognized as a means for increasing the efficiency of operation.

The accompanying drawing illustrates in FIGURE l a refrigerated cabinethaving nozzle means characterized by the features of this invention. Thecabinet 10 includes a top wall 12, a bottom wall 14, a back wall 16 anda front wall 18. The front wall 18 defines an opening 20 which providesaccess to the interior 22 of the refrigerated cabinet. An inner wallv 24defines the extent of the refrigerated space.

A partition 26 is formed to define an inner passage 28 and an outerpassage 30 in the construction. The inner passage 28 carries a-refrigerating means 32 and a circulating fan 34 provides for movementYof air past the refrigerating means and through the passage 28. Asimilar circulating fan 36 is provided for the outer passage 30.

Inlets 38 are provided for eachof the passages 28 and 3f). The streams40 and 32 which cross the access opening pass into these inlets and aredriven through the passages to outlet nozzles 44 and 46. Screens may beincluded over the inlets 38 to prevent entry of insects or other foreignmaterial into the passages.

Specific forms for the nozzle constructions of this invention are shownin FIGURES 2, 3, 4, 5, 6, 7 and 8. In each, the nozzle lconstruction 46provided for the inner passage 28 comprises a honeycomb section having aplurality of aligned passages extending parallel to the walls which denethe passage 28 beyond the corner 48. In the particular embodiment shownfor the nozzles 46, the edges 50 of the nozzles begins at a point belowthe wall 52 which defines the lower extent of the pas'- sage 28. Thestream of air in the passage 28 will be preferentially directed to theouter passages of the nozzle 46 by reason of this arrangement. It hasbeen found that the inner portions of the stream 42 which contact therelatively still air within the cabinet move more slowly than the outerportions of this stream. This arrangement tends to reduce thepossibility of turbulence between this inner stream and the air withinthe cabinet.

In the modification shown in FIGURE 2, the nozzle for the outer streamis formed in two sections 54 and 56. The upper section 54 comprises agenerally triangular member having the hypotenuse thereof extending on aline between the edges 58 and 60 which define the corners in the passage30. The base of the upper section 54 is in a horizontal position; and,therefore, the passages in the section 54 are at an acute angle withrespect to the side walls which define the passage 30.

The lower section 56 comprises a plurality of passages which are alignedin a parallel relationship with respect to the side walls. It will beappreciated that .streams of air passing through the section 54 will bepreferentially directed toward the inner passages in the section 56.With this arrangement, a lower speed is achieved in those portions ofthe air issuing from the outer passages and, accordingly, a decrease inturbulence with respect to the ambient air can be realized.

In the construction shown in FIGURE 3, two sections 62 and 64 are alsoprovided for forming the nozzle of the outer stream. In this embodiment,the passages in the honeycomb sections are all arranged in a parallelrelationship; however, slower movement in the outer portions of theouter stream is achieved because of the curvilinear character of thesection 62. The more pronounced curvature which characterizes thissection at the inner portions thereof causes this section to pick upgreater amounts of air in these inner portions. A slower movement thenresults with respect to outer portions of the stream and, again, areduction in turbulence can be achieved.

In the modification shown in FIGURE 4, the outer stream must passthrough a nozzle 66 which is substantially larger than the nozzle 46.The longer passages in the nozzle i66 result in a greater drag on theair passing therethrough. As a result, the speed of the outer streamwill tend to be slower than the speed of the adjacent inner stream.Furthermore, the angular disposition of the top edge 68 of the nozzle 66provides for longer nozzle passages for carrying the outer portions ofthe stream 40 while the inner passages of the nozzle becomeprogressively smaller. The outer portions of the air stream 40 are,therefore, subjected to a greater drag and, accordingly, these outerportions will have a lesser tendency to create turbulence.

The construction shown in FIGURE 5 employs louver means 70 which issituated in the passage 30 in advance of nozzle 72. It will be notedthat each of the elements 74 which define the louver means is directedat an angle whereby air in the passage will be forced inwardly withrespect to the cabinet enclosure. Each of these elements 74 extends theentire length of the cabinet whereby the channels defined between theelements will also extend across the cabinet. It is contemplated thatreenforcing means can be provided at one or more intermediate pointsbetween the adjacent elements to provide a substantially rigidstructure.

The louvered arrangement illustrated acts to direct air in the passage30 toward the inner side of the honeycomb. This has the effect ofreducing the rate of movement of the air in the outer portion which isexposed to the ambient air.

The arrangement shown in FIGURE 6 comprises a combination of screenelements 76 and means 78 which denes openings 80 for passage of air tonozzle 82. As in the previous cases, the arrangement for effecting thecharacteristics ofthe air is provided in the passage 30.

A plan view of the means 78 shown in FIGURE 6 is illustrated in FIGURE7. As shown therein, a plurality of slats 84 are provided in spacedapart relationship whereby the openings 80 will be defined therebetween.It will be noted that the openings become progressively larger as theyoccur from the outer portion of the means 78 to the inner portionthereof. This arrangement also has the effect of directing a majorportion of the air at the inner side of the passage 30 while lesserportions thereof pass in the portion of the outer stream adjacent theambient air.

FIGURE 8 illustrates a proposed modification 78' wherein progressivelylarger openings 80' approximately correspond in function to the openings80. It will be apparent that this arrangement will affect the air streamin substantially the same manner as described above. The screen 76,which may be conventional window screen, has been found to be adesirable addition since it has the effect of breaking up the air sothat it will not pass through the outlet nozzles in the form of jets.This results in a smoother gradient of air speed across a given panel aswill be discussed with reference to FIGURE 2.

FIGURE 2 illustrates diagrammatically the results which can be achievedwith the nozzle constructions of this invention. In this diagram, thehorizontal axis corresponds to the width of the nozzles employed in theconstruction. When the speed of a stream across this width Ais plottedas illustrated, the desirable character of the streams issuing from thenozzles will be appreciated. With respect to the nozzle sections 54 and56 in FIGURE 2, the X designations on the diagram are employed to plotthe speed of the stream across lits width. It will be noted that arelatively slow air velocity is achieved in the outer 'portions of thestream while a relatively high air velocity is achieved in the innerportions. The circles plotted along with the X on the diagram illustratethe findings with the upper section 54 removed. As noted, the outerportions of the stream actually move at a higher rate than the innerportions. The greater possibility of turbulence with this arrangementwill be obvious.

The right-hand section of the diagram illustrates the affect of thenozzles 46 on the speed of the refrigerated streams. As noted, thelowest speed is achieved in the innermost portions of the stream and,therefore, a decrease in turbulence in this region can be accomplished.

Where the outer nozzles are concerned, it will be understood that thesenozzles are to be employed in any position where. the streams passingtherethrough will contact other air having a substantially lower rate ofmovement; or in the case of ambient air, having substantially nomovement. The nozzle yconstructions may be utilized in cabinets of thetype described by Beckwith et al., 4in application Serial No. 247,245,filed December 26, 1962, and entitled Refrigerated Cabinet WithCirculating' Air Panels. In this construction, an outer stream which wasnot powered by any mechanical circulating means was included. Thenozzles of this invention could be employed for the intermediatepassages in such a construction.

From the above description, it will be apparent that constructions havebeen described which serve to affect the characteristics of moving airstreams in a desirable fashion. The constructions described accomplish arelatively low discharge air velocity in the outer edge of the outerguard stream. At the same time, these constructions accomplishrelatively high velocity at the interface between the refrigeratedstream and the guard stream. It has been found that the use ofarrangements of the type described will greatly improve the operatingefficiency of refrigerated enclosures. The arrangement permits the useof larger air curtains to thereby increase the size of an accessopening. A construction employing these arrangements has less compressorrunning time, less buildup of frost and also reduces air spill-out sothat a person standing in front of the freezer will not be annoyed bycontact with a cold air stream. In considering the above advantages, itwill be appar-ent that similar advantages are available in otherconstruction employing the units of this invention.

Itvwill be understood that various changes and modifications may be madein the constructions illustrated herein which provide thecharacteristics of this invention without departing from the spiritthereof particularly as defined in the following claims.

That which is claimed is:

1. In .a refrigerated cabinet of the type which defines 'an accessopening in one wall communicating an otherwise enclosed space with theambient atmosphere, and which is provided with .a plurality of airinlets and a plural-ity of air nozzles, said inlets and nozzlesextending in side-by-side relationship across opposite edges of saidaccess opening, passages defined by said cabinet cornmunicating each ofthe corresponding inlets and nozzles, refrigeration means disposed inthe innermost one of said passages to refrigerate `at least theinnermost stream, and circulating fans located in said innermost passageand in an immediately adjacent outer passage, the improvement whereinsaid nozzles comprise honeycomb sections, the honeycomb section for saidouter stream including an outer portion adapted to progressively reducethe speed of the outer portion of the air stream-passing therethroughwhereby the extreme outer portion of the stream crossing said accessopening sets up a minimum of turbulence when contacting the ambient air,said `honeycomb section for said outer stream including two spaced-apartupper and lower portions, the passages through the lower portion beingpositioned substantially parallel to the side -walls of the passageconfining the honeycomb section, and the passages through said upperportion being directed inwardly at an acute angle with. respect to saidfirst mentioned passages.

2. A cabinet in accordance with claim 1 wherein the upper portion ofsaid honeycomb section is fixed in position `at the upper corner definedby the passage for said adjacent outer stream, and wherein said upperportion has a generally triangular cross section with the hypotenusethereof extending angularly inwardly at said corner and with the basethereof being disposed .approximately horizontally. l

3. -In a refrigerated cabinet of the type which defines an yaccessopening in one wall communicating an other- Wise enclosed space with theambient atmosphere, and which is provided with a plural-ity of airinlets and a p lurality of air nozzles, said inlets and nozzlesextending in side-by-side relationship across lopposite edges of saidaccess opening, passages deiined by said cabinet communicating each ofthe conresponding inlets and nozzles, refrigeration means disposed inthe innermost one of said passages to refrigerate at least the innermoststream, and circulating fans located in said innermost passage and inVan immediately adjacent outer passage, the iinprovement wherein saidnozzles comprise honeycomb sections, the honeycomb section for saidouter stream including an outer portion adapted to progressively reducethe speed of the outer portion of the air stream passing therethroughwhereby the extreme -outerportion of the stream crossing said accessopening sets up a minimum of turbulence when contacting the ambient air,said honeycomb section for said outer stream including two spacedapartupperand lower sections, said upper section being fixed at a cornerdefined by the outer passage for said outer stream and wherein thepassages defined in both portions of said honeycomb section are`approximately parallel with respect to each other.

4. A cabinet in accordance with claim 3 wherein the upper surface ofsaid upper section is curvilinear to the extent that a greater exposureto said outer streamis presented by the inner passages of said uppersection where- =by the speed of the inner portions of said outer streamexceeds the Ispeed of the outer portions thereof.

5. In a refrigerated cabinet of the type which defines an Iaccessopening in one wall communicating an otherwise enclosed space with theambient atmosphere, and which is vprovided with a plurality of airinlets and a plurality of air nozzles, said inlets and nozzles extendingin side-by-side relationship across opposite edges of said accessopening, passages defined by said cabinet communicating ea-ch of thecorresponding inlets and nozzles, refrigeration means disposed in theinnermost one of said passages to refrigerate at least the innermoststream, and circulating vfans located in said innermost passage and inan immediately adjacent outer passage, the improvement wherein saidnozzles comprise honeycomb sections, the honeycomb section for saidouter stream including an outer portion adapted to progressively reducethe speed of the outer portion of the air stream passing therethroughwhereby the extreme outer portion of the stream crossing said laccessopening sets up a minimum of turbulence when contacting the ambient air,said honeycomb section for said adjacent outer stream deningsubstantially longer passages than the honeycomb section for theinnenmost stream whereby a greater drag is presented by said outerhoneycomb section to effect a reduced speed in the outer stream. v

6. A cabinet in accordance with claim wherein the passages defined bysaid outer honeycomb section gradually increase in length in an outwarddirection whereby the outer portions ofthe outer stream passingtherethrough are subjected to a greater drag than the inner portions ofsaid stream. I

7. `In arconstruction of the type dening an open side and including airinlet means and a plurality ofv air nozzles extending in side-bysiderelationship across opposite edges of said open side, passages definedin said construction communicating each ofthe corresponding inlets `andnozzles, Iand circulating means located inv-at least one of saidpassages for driving air streams through said passages and -across saidopen side between corresponding inlets and nozzles, said air streamscrossing said open side in sideby-side contacting relationship, theimprovement compri-sing imeans for controlling the velocity of the airstreams issuing from said nozzles, said last mentioned means providingfor maxim-um velocity in said air streams at the interface thereof andfor progressively decreasing velocity toward the outeredges of said airstreams, said means for affecting the velocity `of the vair streamscomprising elements in the outer passage of said construction locatedadjacent to and upstream of the nozzle for said outer passage, saidelements Operating to direct a maximum amount of air toward the interiorportion of said Iouter stream to effect a maximum speed of this air atsaid interface.

8. In a refrigerated cabinet of the type which denes an access openingin one wall communicating an otherwise enclosed space with the ambientlatmosphere, said cabinet being provided with a plurality of air inletsand a plurality of air nozzles, said -inlets and nozzles extending inside-by-side relationship across opposite edges of said access opening,passages communicating each of the corresponding inlets and nozzles,refrigeration means disposed in at least the innermost one -of saidpassages to refrigerate at least the innermost stream passing throughsaid passages and across said access opening, and circulating meansincluded in said innermost passage and in an adjacent outer passage formoving the streams of air? through said passages, the improvementcomprising means for controlling the velocity of the air streams as theyissue'from said nozzles, said last mentioned means cornprising elementspositioned in said passages for contact with the stre-ams passingtherethrough and operating to provide a maximum Velocity at theinterface between the streams moving across said access opening withprogressively decre-asing velocity toward the outer edges of saidstreams. Y

9. A cabinet in accordance with claim -8 wherein the means forcontrolling the velocity of the air streams comprise louvers extendingacross the passage coniining the outermost stream, said louvers beinglocated adjacent to and upstream of the nozzle for said outermoststream, and air channels deiined by said louvers directed down wardlyand inwardly toward said last mentioned nozzle whereby faster movingportions of the outermost air stream are provided in the innermostsections thereof.

l 10. A cabinet in accordance with claim -8 wherein the means forcontrolling the velocity of said air streams comprise elements extendingacross the passage confining the Ioutermost air stream, said elementsbeing located adjacent to and upstream of thel nozzle for said outermostpassage, said elements dening openings extending across said passagewith said openings being progressively larger` toward the inner portionsof said passage whereby a greater speed is produced in the innermostportions of the air stream in the outermost passage.

11. A cabinet in accordance with claim 10 wherein screens are locatedimmediately upstream of said elements.

References Cited by the Examiner UNITED STATES PATENTS 3,021,776 2/1962Kennedy 98-36 3,163,024 12/1964 Beckwith 98-36 X WILLIAM F. oDEA,Primary Examiner.

JOHN F. OCONNOR, Examiner.

1. IN A REFRIGERATED CABINET OF THE TYPE WHICH DEFINES AN ACCESS OPENINGIN ONE WALL COMMUNICATING AN OTHERWISE ENCLOSED SPACE WITH THE AMBIENTATMOSPHERE, AND WHICH IS PROVIDED WITH A PLURALITY OF AIR INLETS AND APLURALITY OF AIR NOZZLES, SAID INLETS AND NOZZLES EXTENDING INSIDE-BY-SIDE RELATIONSHIP ACROSS OPPOSITE EDGES OF SAID ACCESS OPENING,PASSAGES DEFINED BY SAID CABINET COMMUNICATING EACH OF THE CORRESPONDINGINLETS AND NOZZLES, REFRIGERATION MEANS DISPOSED IN THE INNERMOST ONE OFSAID PASSAGES TO REFRIGERATE AT LEAST THE INNERMOST STREAM, ANDCIRCULATING FANS LOCATED IN SAID INNERMOST PASSAGE AND IN AN IMMEDIATELYADJACENT OUTER PASSAGE, THE IMPROVEMENT WHEREIN SAID NOZZLES COMPRISEHONEYCOMB SECTIONS, THE HONEYCOMB SECTION FOR SAID OUTER STREAMINCLUDING AN OUTER PORTION ADAPTED TO PROGRESSIVELY REDUCE THE SPEED OFTHE OUTER PORTION OF THE AIR STREAM PASSING THERETHROUGH WHEREBY THEEXTREME OUTER PORTION OF THE STREAM CROSSING SAID ACCESS OPENING SETS UPA MINIMUM OF TURBULENCE WHEN CONTACTING THE AMBIENT AIR, SAID HONEYCOMBSECTION FOR SAID OUTER STREAM INCLUDING TWO SPACED-APART UPPER AND LOWERPORTIONS, THE PASSAGES THROUGH THE LOWER PORTION BEING POSITIONEDSUBSTANTIALLY PARALLEL TO THE SIDE WALLS OF THE PASSAGE CONFINING THEHONEYCOMB SECTION, AND THE PASSAGES THROUGH SAID UPPER PORTION BEINGDIRECTED INWARDLY AT AN ACUTE ANGLE WITH RESPECT TO SAID FIRST MEMTIONEDPASSAGES.